JP2808686B2 - Electronic depth gauge - Google Patents

Description

Description: TECHNICAL FIELD [0001] The present invention relates to an electronic water depth gauge that calculates a water depth from a pressure detected by a pressure sensor.

[Prior art and its problems]

In a depth gauge that determines the water depth from the pressure detected by the pressure sensor, the water depth calculated from the pressure in the water detected by the pressure sensor due to the fluctuation of the atmospheric pressure at the measurement point or the influence of the altitude of the measurement point, etc. May be different. Therefore, for example, before starting the measurement, the pressure at the reference point (for example, the pressure on the water surface) is set in advance as the reference pressure,
The water depth is calculated from the pressure difference between the reference pressure and the pressure detected by the pressure sensor during diving.

For example, when switching from the watch mode to the depth gauge mode is performed, if the pressure detected by the pressure sensor is taken as the reference pressure, the switch to the depth gauge mode is correctly performed before the start of diving. If so, the correct reference pressure is set and the correct water depth at the dive point can be obtained.

However, sometimes the user forgets to switch the mode and switches to the depth gauge mode underwater. In this case, since the pressure at a point in the water at the time of the mode switching is taken in as the reference pressure, the water depth calculated based on the reference pressure is shallower than the actual water depth.

As a result, there is a problem that the water depth shallower than the actual water depth is erroneously displayed, which is a serious drawback relating to the life of the diver.

[Object of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic depth gauge capable of preventing an erroneous pressure from being set as a reference pressure and displaying a correct depth.

[Gist of the invention]

The present invention provides a water depth gauge that calculates a water depth from a set reference pressure and a pressure detected by a pressure sensor. When a setting of a reference pressure is instructed by a switch, the pressure sensor detects the reference pressure as a reference pressure to be set. When the pressure to be applied is equal to or higher than a predetermined pressure, a predetermined specific pressure is set as a reference pressure, and it is possible to prevent a pressure measured in water or the like from being erroneously set as a reference pressure.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit configuration diagram of an electronic wristwatch with a depth gauge according to one embodiment of the present invention.

The oscillating circuit 1 is a circuit that generates a clock signal having a constant period, and outputs the generated clock signal to the frequency dividing circuit 2. The frequency dividing circuit 2 divides the frequency of the clock signal.
A clock signal of 1 Hz is created and output to the clock circuit 3.

The clock counting circuit 3 counts the 1 Hz clock signal, obtains time data including the current time and date, and outputs the time data to the CPU 4. Further, it outputs a measurement timing signal of 1/3 Hz, which is a reference of the water depth measurement, to the CPU 4.

The CPU 4 is a central processing unit that controls the entire circuit,
For example, in the clock mode, the time is updated based on the time data from the clock circuit 3, and in the water depth gauge mode, a pressure sensor 5 or the like described later is driven every three seconds to perform the water depth measurement.

The pressure sensor 5 is a sensor that detects the atmospheric pressure or the water pressure, and outputs an analog pressure signal corresponding to the pressure to the amplifier circuit 6. The amplification circuit 6 is a circuit that amplifies an analog pressure signal from the pressure sensor 5 to a predetermined signal level. The analog pressure signal amplified by the amplification circuit 6 is converted into a digital pressure signal by the A / D conversion circuit 7 and output to the CPU 4. In addition, these pressure sensors 5,
The amplification circuit 6 and the A / D conversion circuit 7 operate in accordance with the drive signal given every three seconds from the CPU 4 to perform water depth measurement.

Switching unit 8, illustrated non Although mode switch S _M for switching the watch mode and the depth gauge mode is composed of a time adjustment switch for operating when the time correction in watch mode, these operations signals CPU4 Output to

The RAM 4 is a memory for writing and reading under the control of the CPU 4, and as schematically shown in FIG. 1, a register P for storing a measured pressure, a register P ₀ for storing a reference pressure, an operation mode And a mode register M for storing a numerical value corresponding to.

The display drive circuit 10 outputs time data output from the CPU 4,
A circuit for converting water depth data and the like into a signal for driving a display element of the display unit 11, and outputs the generated display signal to the display unit 11.

The display unit 11 is composed of a liquid crystal display or the like, and displays the current time, the depth of the dive point, and the like.

Next, the operation of the embodiment having the above configuration will be described with reference to the flowcharts of FIGS.

FIG. 2 is a flowchart for explaining the overall operation of the embodiment.

First, in step S1 of FIG. 2, it is determined whether any switch has been operated.

When the switch is operated, the switch process of the next step S2 is executed.

Hereinafter, this switching process will be described with reference to the flowchart of FIG.

First, in step S11 of FIG. 3, it is determined whether or not the mode changeover switch _SM is operated.

When the engineered was switch S _M is the value of the mode register M proceeds to step S12 to determine whether "0".

When M = 1, that is, when the switch _SM is operated in the depth gauge mode, the process proceeds to step S13, where "0" is set in the mode register M, the mode is switched to the clock mode, and the switch processing is terminated.

On the other hand, when M = 0, that is, when the switch _SM is operated in the clock mode, the process proceeds to step S14, where "1" is set in the mode register M, and the mode is switched to the depth gauge mode.

Then, in the next step S15, the pressure detected by the pressure sensor at that time is stored in the register P. afterwards,
In step S16, the detected pressure is set to a predetermined pressure value [for example, 1 m below sea level under a standard atmospheric pressure (1.033 kg / cm ² )].
Is smaller than 1.136 kg / cm ² ].

When P <of 1.136kg / cm ² is determined not intended operation of the switch S _M is performed in water, and stores the pressure value P measured current the process proceeds to step S17 to register P ₀ as a reference pressure.

On the other hand, if P ≧ 1.136 kg / cm ² in the determination in step S16, it is determined that the switch to the depth gauge mode was erroneously performed in the water and the pressure in the water was taken in as the reference pressure. Proceeding to S18, the pre-stored pressure at sea level (0 m) under standard atmospheric pressure 1.
The 033kg / cm ² stored in the register P ₀ as a reference pressure.

In this way, it is determined whether the value taken as the reference pressure at the time of mode switching is smaller than a predetermined pressure value (for example, 1.133 kg / cm ² ). Since the pressure of the lower sea surface (1.033 kg / cm ² ) is set as the reference pressure, the pressure at the dive point is not set as the reference pressure even if the mode is switched accidentally during diving.

Therefore, the water depth shallower than the actual water depth is not displayed, and it is possible to prevent the diver from accidentally diving to a deep water depth.

In the determination of step S11, engineered for unless the switch S _M is, it is when the other switches such as time adjustment is operated to perform a switching process corresponding to the process proceeds to step S19.

After the switch process is completed as described above,
Proceeding to step S3 in FIG. 2, it is determined whether the value of the mode register M is "1".

If M = 0, the mode is the clock mode, and the flow advances to step S4 to display the time data from the clock counting circuit 3 on the display unit 11.

If M = 1, it is in the depth gauge mode and the step
Proceeding to S5, it is determined whether or not the measurement timing is every three seconds.

If the measurement timing is not every three seconds, the process directly proceeds to the display process in step S7, and the water depth calculated from the pressure stored in the register P is displayed on the display unit 11.

On the other hand, when the measurement timing is every three seconds, the measurement processing of the next step S6 is executed.

Hereinafter, this measurement processing will be described with reference to the flowchart of FIG.

First, at step S21 in FIG.
The pressure data detected every second is stored in the register P. Then, the difference between the measured pressure and the reference pressure of the register P ₀ of the register P in the next step S22, divided by the pressure increase value 0.10256kg / cm ² per seawater 1m to calculate the depth of that point.

After the water depth at the dive point is calculated by the measurement processing in this way, the display processing in step S7 in FIG. 2 is executed, and the calculated water depth is displayed on the display unit 11.

As described above, according to the above-described embodiment, even if the pressure at the dive point during dive is erroneously taken as the reference pressure, if the pressure is equal to or higher than the predetermined pressure value, the pressure of the sea surface under the standard atmospheric pressure Is set as the reference pressure, so that a water depth shallower than the actual water depth is not displayed, and an erroneous water depth can be displayed to prevent danger to the diver.

In the above embodiment, the pressure detected by the pressure sensor at the time of mode switching is taken as the reference pressure. However, the present invention is not limited to this, and can be applied to a pressure gauge having another configuration. For example, the present invention can be applied to a case where a switch for instructing input of a reference pressure is provided and a pressure measured when the switch is operated is taken in as a reference pressure.

Further, the predetermined pressure value serving as a criterion for determining whether the measured pressure is set as the reference pressure or whether a specific pressure value stored in advance is set as the reference pressure is the value described in the embodiment, 1.136. The value is not limited to kg / cm ² , but can be set to any value within a range that can ensure the safety of the diver.

Further, the present invention is not limited to the one in which the depth gauge described in the embodiment is incorporated in an electronic wristwatch, but may be incorporated in other devices, and may be a device dedicated to the depth gauge.

〔The invention's effect〕

According to the present invention, since the pressure in the water is not erroneously set as the reference pressure, a water depth shallower than the actual water depth is displayed, and the diver can be prevented from diving to a dangerous water depth.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of an electronic wristwatch with a water depth gauge according to an embodiment of the present invention, and FIGS. 2, 3 and 4 are flow charts for explaining the operation of the embodiment. 4 ... CPU, 5 ... Pressure sensor, 9 ... RAM.

Claims (1)

(57) [Claims] 1. An electronic depth gauge for determining a water depth from a set reference pressure and a pressure detected by a pressure sensor, comprising: switch means for instructing the setting of a reference pressure; and setting of the reference pressure by the switch means. When done
When the pressure detected by the pressure sensor is lower than a predetermined pressure, the detected pressure is set as a reference pressure, and when the detected pressure is equal to or higher than a predetermined pressure, the predetermined pressure is set as a reference. An electronic water depth gauge comprising: a reference pressure setting means for setting a pressure.